So I've built this one yesterday and I would greatly appreciate your opinion as I have little knowledge about the functionalities and possibilities of eurorack systems. I really want to include a Maths too so please let me know whether some modules can be changed.
i'm not an expert either, BUT looking at your system, you have a duophonic with 2 analogue VCOs... if that's all you have, it looks like you have too much mixer for your little system and could get by with a smaller & cheaper one like doepfer's
A-138b https://www.modulargrid.net/e/doepfer-a-138b as you'd only have TWO audio chains. that would free your rack up for other modules. the quad VCA seems like overkill for your system too as you only need 2 VCAs max, and your mother 32 already has its own VCA, so you're wasting 3 channels, money, and rackspace that you don't need to (unless you were mixing & matching different types like tubes & vactrols for different tones). you'd also be better served with getting a single dual channel VCA (optomix, with its 2 vactrol channels is popular & would add to the sound of your moog VCA if you patched into that, intellijel's "regular dual VCA" is popular too) and an envelope generator, particularly an ADSR as you need that to control the envelopes for your second voice.
i have no opinion on the hadron collider VCF, but the minimod ladder filter seems redundant as its another moog filter. why not get something DIFFERENT so you could add to the types of sounds you can make? doepfer's WASP filter is popular, cheap AND is available in black. it would give you some very different distorted tones while saving you money & rackspace to expand your sounds and/or abilities, eg. ring modulation. a good multimode filter like intellijel's polaris will not only take less space up, but also give you all kinds of tones your "2x moogs" won't like JUICY. you could also go with a different synth clone filter eg. SEM, ARP, or korg MS-20 etc. as each of those will give you different tones, or you get get REALLY radical & get a bright yellow rack hogging metasonix tube VCF for radical distortion effects.
personally, i'm biased AGAINST the "moog sound". it reminds me of bad sci-fi movies whereas ARP & SEM filters have a "classier" (to me) sound that's juicier & has more character, but you really have to audition filters in youtube videos to hear which ones YOU like. plenty of people love moog sound. i'm just not one of them. i's take am R2D2 sqeaking ARP 2600 over a moog any day, if nothing else, because tit offers modules that aren't common on moogs.
the tiptop VCO is popular, for sure, and not bad, BUT you already have an anologue moog oscillator. why not expand your tone potential with a wavetable oscillator like erica synth's popular black one? if you wanted another analogue oscillator, intellijel's dixie II+ is very popular & doesn't take a lot of rack space up. there's SUPPOSED to be something "special" about triangle core VCOs, but i don't know what it is. still, a dixie takes up half the space of the tiptop & a wavetable one would give you TONS of different tones you can't get out of an analogue. while it would REALLY reat your rackspace up, intellijel's cylonix shapeshifter is an INSANE oscillator (has its own SEPARATE wave folder BTW) that includes all kinds of vocoder effects and just really deep and crazy stuff that virtually makes it a standalone synthesizer. if you watch this demo, you'll see SOME of the crazy things it can do that were driving the EXPERIENCED reviewer out of his mind
i'd gladly trade "boring" utilities for that kind of tonal mayhem, but that's me. even if you didn't want to go that route, virtually ANY wavetable VCO will give you all kinds of tones that anologue filters with just sine, sawtooth, triangle, square & pulse width can't do.
also, adding a noise generator will add to your tone even if you stay totally analogue. i'm not sure if the mother 32 does noise. it's kind of limited.
the two power adapters seems overkill, especially when you can internally power a rack, probably cheaper, but you have to do the math & choose the right box. according to this site, you only need 968 milliamps positive and 333 negative worth of power. you could probably buy a rack that can handle that easily. i think people only use power modules on big power hungry systems.
i'm not familiar with your sequencer choice, but if it doesn't offer LFO & clock modulation, then pamela's new workout is a pretty powerful 8 channel clocking utility that's also programmable, though the more analogue batumi is probably more popular. one of those might help if you free some rack space up.
another total rack hog i'd replace pretty much ALL of your utilities, INCLUDING your sequencer with is rossum's control forge. it's like a wavetable LFO/sequencer for voltages. you can program 8 step voltage sequences (& link them, apparently) to create really long sequences, but best of all, you can control the CURVES and TIMES between steps to do all kinds of timing changing effects you can't get out of regular (i HATE 'EM!!! LOL) sequencers, not be stuck with "same old same old" linear transitions as you can choose each step's "curve" and then EDIT IT further and do some crazy granular, crossfade & wobble stuff i don't think anything else does. best of all, like with the pamela's new workout, you can SAVE presets!!!
modulars are very personal. MOST modular fans, it seems, like lots of utilities they can noodle with & create automations. not me. i prefer adjustment knobs over patch jacks every time. that's probably another reason i like control forge... you can do everything within the one module and get visual feedback from the display. for ME, it would be the BASE for much of my sound... creating lopsided ahhh-whoops, bass wobbles, scratches & boings & maybe even doing sequences along with an envelope follower module that i could use to human beatbox CVs with, but my approach is almost totally PLAY the rack instead of letting it play itself while you just twist knobs.
the best thing to do is let you take a look at control forge and decide for yourself if it's either interesting or a pointless complicated toy. it totally blew my mind though as it's VERY CLOSE to a module i imagined that i didn't know existed. analogue modules have sooooo many limitations that have been around half a century with no progress, but you can do so many more complicated things with digital. you can HAND DRAW modulations in a DAW sequencer, EDIT sequences with far more resolution, create an unlimited variety of waves (oscillators), create complex modulations, and even create crazy filters that do what analogue can't (rossum's sick morpheus z-plane rack hogging digital filter)
back to control forge... here's food for thought for you...
hopefully SOMETHING i've said helps you find YOUR SOUND
again, your triple wave folder is overkill as you only have 2 oscillators. it's better suited for a big system AND, back to wavetable VCOs, they'll give you way more variety than an analogue/wavefolder combo. if anything, get a small & cheap wavefolder like a doepfer and their small & cheap ring modulator for additional tone mangling potential.
you chose a harvistam polivoks filter... OK, but, you can get a smaller erica synths one that would match your black row, & back to envelope followers, get their polivoks to match. personally, i like larger roland & intellijel dual ADSRs because they're dual and moreso, use sliders which are more visual than knobs, but you can't go wrong with a cheap doepfer ADSR or two if you're OK with knobs.
i'm not too into the joystick mixer thing, but i wouldn't be using a rack for live noodling. if you kept it in your rack, you really wouldn't need the extra mixer for all the extra audio you don't have. the joystick would cover your entire system well enough as you'd only be mixing 2 voices or maybe 3-4 if you run more than one VCF per voice and want to morph between voices or blend them. the extra mixer is both overkill & redundant in your small system.
as to utilities, i won't comment on those. they're very personal, and necessary for noodling. that, and they generally don't agree with my simpler synthesizer with multiple voice options approach. i prefer to control modulations myself or with a computer sequencer using a midi in module.
using MY BIASES, i would aim for a bit more flexibility in tone &cut back on the redundancy... then, i'd get rid of all the utilities and add MORE VCOs & VCFs, but that's me. i don't do complicated patches. noodling doesn't sound interesting to me at all, but then again, i DESPISE perfect timing quantization.
HA!!!! the forum TRIED to waste my time & delete this reply by logging me out, BUT, now i know to back up & copy long replies BEFORE logging back on when attempting to reply, then paste it after logging back in! i've lost a couple really long replies already which drives me nuts!
i'm not an expert either, BUT looking at your system, you have a duophonic with 2 analogue VCOs...
My friend, it seems like you are a eurorack master and literally one of THE MOST experienced persons on the field! Words can't describe how much I appreciate your effort into explaining EVERYTHING in detail and giving me a better understanding as to what is best for a system, how to save money and most importantly, providing a deep coverage on the technical side of things. Believe me, your explanation will be my bible into designing my next one.
Maybe you are right about the moog sound, I am a bit obsessed with it and in that case I overdone it! I'll edit this one and will be definitely removing the ladder filter. Checking the videos now and will get back to you.